Limiting sugar in toddlers could cut risk of dementia, study suggests

Denying sugar to children before the age of two could cut their risk of dementia in later life.

There are currently estimated to be 982,000 people with dementia in the UK, with more than a third of those without a diagnosis.

Eating too much sugar has previously been linked to type 2 diabetes, which causes damage to blood vessels and can increase the risk of dementia.

But a study suggests it’s not just adults who should reduce sugar intake – stopping children under the age of two from having sugar can also have lasting effects on their brain health.

Researchers in China found babies who have very little sugar before in-utero birth and before the age of two had a 23 per cent lower risk of developing dementia later in life.

“Our findings suggest that limiting sugar during the earliest stages of life may have lasting benefits for brain health,” said study author Dr Jiazhen Zheng, at the Hong Kong University of Science and Technology in Guangzhou, China.

“These results highlight the potential importance of early-life nutrition in reducing the risk of dementia decades later.”

For the study, published in the journal Neurology, researchers looked at data from 64,737 people born before and after World War II sugar rationing in the UK. Sugar was rationed during and after the war and then became widely available again in 1953.

Participants were grouped by when sugar rationing occurred: before birth and during their first year, before birth and up to two years old, or no sugar rationing.

Starting when participants were an average age of 55, researchers used medical records to determine which participants were diagnosed with dementia up to 15 years later.

Of 15,025 who experienced sugar rationing before birth and during their first year of life, 388 developed dementia. Of 15,256 who experienced sugar rationing before birth and during their first two years of life, 456 developed dementia. Of 23,774 born after sugar rationing, 504 developed dementia.

After adjusting for health factors like high blood pressure and diabetes, researchers found people who experienced sugar rationing before birth and up to one year old had a 21 per cent lower risk of dementia compared to people born after sugar rationing.

Those who experienced it before birth and up to two years old had a 23 per cent lower risk of dementia. Dementia was also delayed by an average of 2.6 years in people who consumed lower sugar levels early in life.

A smaller group of participants also had brain scans. People with less sugar in early life had higher total grey matter volume and lower levels of white matter hyperintensities – a sign they have less brain tissue damage.

Dr Zheng added: “Limiting added sugars during pregnancy and infancy may be one beneficial step that families and communities can take, but further research is needed to better understand how these early exposures influence dementia risk and to guide public health strategies.”

Dr Sara Rodrigues, senior research manager at Alzheimer’s Research UK, said: “Research like this helps us better understand how dementia risk develops across our lifetime and could help shape future approaches to protecting brain health.

“However, it’s important to remember that this was an observational study. This means it can identify links between diet and dementia risk, but it cannot prove that eating less sugar directly prevents dementia.

“The Lancet Commission – one of the most comprehensive reviews of dementia risk – does not currently list sugar intake as a standalone risk factor.

“More research is needed to better understand the potential relationship between sugar intake and the development of dementia.”

She added advice from Alzheimer’s Research UK remains unchanged and encouraged people to eat a balanced diet to support brain health.